False-positive bone lesions mimicking bone metastases (bone pseudometastasis) on 18F-FDG PET/CT have often been reported in patients with esophageal cancer. We aimed to evaluate the prevalence and features of these lesions in Japanese patients with esophageal cancer.
In this retrospective study, we analyzed 83 FDG PET/CT studies for initial staging of esophageal cancer, and extracted patients with 1 or more localized high uptake sites with no subsequent progression, which were therefore judged to be bone pseudometastasis. The FDG PET/CT imaging features of the bone pseudometastasis were evaluated, and other available imaging and clinical features reviewed.
Of the 83 patients, 7 had bone pseudometastasis. All 7 were males diagnosed with squamous cell cancer, of which 5 had T1a tumors. Bone pseudometastasis showed normal or ill-defined hyperdense (nonosteolytic) sites compared with the surrounding area on the CT. Additionally, accumulation in the upper vertebral levels of each case was contiguously high compared with the lumbar spines (we named this finding “contiguous accumulation”). On MRI, these findings were visualized as low signals on T1-weighted imaging (T1WI) and T2WI images but were unclear on fat-suppressed T2WI images.
Among all PET/CT performed for staging of esophageal cancer, 8.3% demonstrated bone pseudometastasis characterized by heterogeneous distribution with severe fatty degeneration of bone marrow accompanied by contiguous accumulation. Caution is required during diagnoses of bone lesions in esophageal cancer patients in Japan to prevent inappropriate therapeutic choices.
From the *Division of PET Imaging, Shiga Medical Center Research Institute, Moriyama
†Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
‡Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto
§Department of Diagnostic Radiology, Shiga General Hospital, Moriyama, Japan.
Received for publication February 28, 2019; revision accepted March 30, 2019.
Conflicts of interest and sources of funding: This manuscript was partly supported by the Grant-in-Aid for Scientific Research (C) from the Japan Society for the Promotion of Science for the cost of English proofreading. The authors state that this work has not received any other funding, and there are no other conflicts of interest to disclose.
Correspondence to: Chio Okuyama, MD, PhD, Division of PET Imaging, Shiga Medical Center Research Institute, 5-4-20, Moriyama, Shiga 524-8524, Japan. E-mail: firstname.lastname@example.org.
Online date: May 17, 2019